Update git submodules

* Update docs/submodules/yardstick from branch 'stable/danube'
  - Bugfix: fix query job status in TC074

    JIRA: YARDSTICK-621
    The storperf job status query in TC074 didn' work properly. The cause is the
    "type: status" is not passed in the URL. This patch also update storperf VM
    image to xenial.

    Change-Id: Idd9f501416b24612f6045a57ba2a95e2ed3a9572
    Signed-off-by: JingLu5 <lvjing5@huawei.com>
    (cherry picked from commit b2fb23ca8ccc1acedaa9156552af4ba347f24103)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 77f471b..132564d 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 77f471be8bd681c7a4d41d0549104e231c437e95
+Subproject commit 132564dc6b19cea9145b23332a04c258d1182f64